In large groups, it can be hard to determine what the members' opinions are. There should be a function that allows the person posting an announcement to add a "Vote Yes/No" button under the announcement. It should also have the option to only show the results to an Admin, who can then announce them himself. The results should show the number of yes/no votes and the number of people who haven't voted.

Similarly, there should be an RSVP option for Events. After all, if no one can attend, then it's a waste of time and should be cancelled.